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Does Dorchester flood?

Dorset
22postcodes in the EA rivers-and-sea dataset
9river gauges within 10 km
2years with a mapped flood record within 5 km
🏠 Thinking of buying in Dorchester? Get the detailed Property Flood-Risk Report for any Dorchester postcode — official risk band, recorded floods since 1703, warning history, river behaviour and nearby storm overflows. £19 one-off, instant. Learn more →

What the Environment Agency's rivers-and-sea flood-risk data says about Dorchester

Ordnance Survey places 22 postcodes in Dorchester in the Environment Agency's rivers-and-sea flood-risk dataset (Risk of Flooding from Rivers and Sea). Each postcode is counted once, under the worst band any of its properties reaches; together they hold 243 properties in the EA dataset's likelihood bands.

EA likelihood bandPostcodes (worst band)Properties in the EA datasetof which homes
High92723
Medium21515
Low11201173
Very low000
All bands22243211

This dataset covers flooding from rivers and the sea only — one of five flood sources. Surface water, groundwater, sewers and reservoirs are assessed separately, so a postcode missing from it is not proof that a place cannot flood. The band describes the land around properties (allowing for defences), not any single address and not today's conditions.

Rivers and live river levels near Dorchester

Environment Agency gauges within 10 km of Dorchester watch River Frome, River Piddle, River Wey.

Distances are from the middle of Dorchester's at-risk postcodes. Tidal and structure gauges are shown as readings only — the tide and sluice gates move them, not floods. A gauge with no recent reading shows no level.

The watercourse nearest Dorchester

The nearest watercourse on the river map is the River Frome, about 50 m from the middle of Dorchester's at-risk postcodes.

A gauge downstream shows water that has already passed this point; one upstream sees it first. Distances along the river are from the point on the River Frome nearest the middle of Dorchester's at-risk postcodes. From Ordnance Survey’s river map (OS Open Rivers), which leaves out small streams, ditches and culverts, so a nearer one may exist. This describes where water goes on the map; it says nothing about flooding at any address. Contains OS data © Crown copyright and database rights 2026.

Flood warning areas near Dorchester

12 Environment Agency flood warning areas lie within 10 km of Dorchester. The EA has issued 582 flood warnings and alerts for them since 2006, most recently on 24 Oct 2026.

Recorded floods near Dorchester

Floods whose mapped extent (EA Recorded Flood Outlines) reached within ~5 km of Dorchester, most recent first. Records, not floods: no outline on the record is not evidence a place has not flooded. See them on the map →

Rainfall near Dorchester

Dorchester gets about 1,122 mm of rain a year on average (wettest month November, 136 mm; driest July, 60 mm). That is close to the UK as a whole, which averages 1,163 mm a year. Source: Met Office HadUK-Grid 1991–2020 (5 km grid), 2.6 km from the place centre.

The nearest rain gauge, Rainfall station (6.4 km away), recorded 11.3 mm in the last 24 hours and 89.4 mm in the last 7 days (latest reading 33 min ago).

At-risk postcodes in Dorchester

Every postcode Ordnance Survey places in Dorchester that appears in the EA's rivers-and-sea dataset, worst band first. Each links to its own flood-risk page.

High likelihood (9)

DT1 1HUDT1 1JGDT1 1LGDT1 1LTDT1 1LXDT1 1PLDT1 1XEDT1 1XUDT1 1XW

Medium likelihood (2)

DT1 1NEDT1 1NF

Low likelihood (11)

DT1 1ABDT1 1LJDT1 1LLDT1 1LQDT1 1LWDT1 1NDDT1 1NQDT1 1PEDT1 1SSDT1 1SXDT1 1WY

Postcode districts

DT1 · 22

Sources

FloodRadar summarises public flood data. It is not a flood-risk survey of any property, and it does not replace official GOV.UK flood warnings or the GOV.UK long-term flood risk service.

Flood-risk bands: © Environment Agency copyright and/or database right 2025. All rights reserved. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, © NERC (CEH). © Crown Copyright and Database Rights 2025 OS AC0000807064. This product is produced in part from PAF® and Multiple Residence Data, the copyright in which is owned by Royal Mail Group Limited and/or Royal Mail Group plc. All rights reserved. Licence number AC0000807064.

Recorded Flood Outlines, flood warning areas and warning history © Environment Agency copyright and/or database right 2025. Licensed under the Open Government Licence v3.0.

River levels and rainfall: Environment Agency real-time flood-monitoring data, updated every 15 minutes (Open Government Licence v3.0).

Average rainfall: HadUK-Grid v1.3.2, Met Office. Contains public sector information licensed under the Open Government Licence v3.0.

Place names: Contains OS data © Crown copyright and database rights 2026. Contains Royal Mail data © Royal Mail copyright and database right 2026. Contains National Statistics data © Crown copyright and database right 2026. Licensed under the Open Government Licence v3.0.

All data sources & licences